Traceback stage for a viterbi decoder
US5987637A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 1997 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Feb 18, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/4169
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a traceback unit for an M-step Viterbi decoder for a convolutionally encoded data stream, each of the traceback stages has a group of K input wires representing K possible candidate states. A bank of K multiplexers selects one of 2.sup.M of the input wires according to M bits of traceback data. The K multiplexer outputs feed a succeeding traceback stage. M groups of K wires carry the traceback data, with each wire being connected to a selection line of each multiplexer. At the output of the traceback unit an identification circuit identifies a subgroup of the K possibilities which has a maximum number of candidate states remaining therein. The arrangement obviates the need for retiming between every traceback stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.